Sentinel Node (SN) biopsy studies have been recently applied to gastric cancer. In this series, 40 selected patients operated for gastric adenocarcinoma located in the lesser curvature and/or anterior wall of the body and antrum, underwent an intraoperative dye lymphography. The lymphatic ducts and nodes were visualized and a SN was evidenced in all cases. This was removed and a frozen section examined. In all cases a radical D2-3 gastrectomy was performed and histology, molecular biology, RT-PCR research of micrometastases (CEA-mRNA), were determined on the specimens. Correlations between T and histological status of SN and regional nodes were done. In 16 cases the SN was negative and all the resected regional nodes were negative too. In 15 cases the SN node was positive and other nodes in other stations were found to be positive as well. In 2 cases the SN was negative but other nodes, in the same stations and in others, were positive (false negative = 5%). In 7 cases the SN was the only node in which metastases occurred, 3 demonstrated by conventional histology and 4 detected by RT-PCR. In these 7 cases the SN was the only involved node out of all resected nodes, thus demonstrating to be the real first node along the lymphatic routes from the tumour. This experience seems to confirm the existence of a Sentinel Node and that each gastric adenocarcinoma has its own lymphatic basin in which metastasis can occur. Although a prudent attitude towards the indications resulting from these observations is required, in selected cases a controlled and tailored lymphoadenectomy could be adopted.